The `Roommate` actress and the `Avengers` actor dated briefly in 2007 but have decided to give things another go and recently rekindled their relationship.
A source said: "She did a number on him back then. But she reached out to Chris this time."
However, Chris wants to take things slowly as he doesn`t want to get hurt again.
The source added to Us Weekly magazine: "He`s still a little insecure, so he`s being cautious."
Chris - who has previously dated Jessica Biel - recently said he wants a girlfriend who isn`t afraid to argue with him and is not bothered by his celebrity status.
The 31-year-old hunk said: "I like ... girls who give me a hard time [and] bust my chops a little. I like girls who aren`t so la-di-da. L.A. is so la-di-da. I like wet hair and sweatpants. I like sneakers and ponytails."
Minka, 32, was recently liked to actor Jake Gyllenhaal after the pair went on a string of dates together and was previously in a long-term relationship with Derek Jeter.